Field of the Invention
This invention relates to a derivative plant promoter inducible by abiotic stress, and host cells and transgenic plants transformed with the abiotic stress-inducible promoter.
Description of Related Art
Abiotic stresses include drought, salinity and extreme temperatures. These stresses, particularly drought, cause extensive losses to agricultural crop production. The ability of crop plants to tolerate drought conditions would be beneficial in reducing these losses.
A plant promoter inducible under abiotic stress conditions is described in PCT/IB2008/054628 (published as WO2009/060402), the contents of which are incorporated by reference. On the whole, in comparison to the high level transgene expression by constitutive promoters, stress-inducible promoters provide poor expression levels of genes in transgenic plants. On the other hand, the stress-inducible promoter, XvPSap1, isolated from the genome of a desiccation tolerant monocotyledonous plant, Xerophyta viscosa, was found to express efficiently. However, the XvPSap1, promoter has a disadvantage in that the sequence is relatively large. The large promoter size is a limiting factor for its use in the development of transgenic plants, as the longer the transgenic DNA sequence, the lower the efficiency of transformation and stability of the trait. As such, this will greatly limit the use of XvPSap1 in biotechnological applications.
A need therefore exists for an abiotic stress-inducible promoter that can be used to transform crop plants and which has a shorter length than XvPSap1, but is still able to function at least as well as XvPSap1.